In the manufacturing of an electronic device such as a semiconductor device, substrate processing is performed using a substrate processing apparatus. As processing performed in the substrate processing apparatus, for example, plasma processing in which etching or film formation is performed using a plasma may be performed.
In a process in such a substrate processing apparatus, different types of processing may be performed on a substrate by sequentially changing gases which are supplied into the same processing container. In order to perform such a process, a substrate processing apparatus is required to include a gas supply system capable of switching different gases to be supplied. As a substrate processing apparatus including such a gas supply system, a plasma processing apparatus is disclosed in the following Patent Literature 1.
The gas supply system of the plasma processing apparatus disclosed in Patent Literature 1 includes a plurality of pipes connected to a plurality of gas sources, a single common pipe connected to the plurality of pipes, and a plurality of branch pipes branching off from the common pipe. A valve is provided in each of the plurality of pipes. A flow rate controller and a valve are provided in each of the plurality of branch pipes. According to the gas supply system, a gas selected among the plurality of gas sources can be supplied to the plasma processing apparatus through the plurality of branch pipes by selectively opening and closing the valves of the plurality of pipes.